cross country move denver to portland in 5 weeks with our 36lb poodle mix and i have now gotten conflicting in-cabin pet policy info from 3 airlines on the same itinerary, how do you actually evaluate which airline is dog-safe vs marketing dog-safe

Quick context. Otis is 4, neutered, 36lb on the nose at his last vet weigh-in two weeks ago, standard poodle / cocker spaniel mix per the embark, mellow temperament, has been on car trips with us up to 11 hours at a stretch without issue, has never flown. our move from denver to portland is locked in for the end of july, my husband is driving the truck with the cats, and i am flying with otis because the cats and otis do not coexist in a confined space and we tried.

here is where i am stuck. otis is right at the size cutoff where in-cabin is technically possible on some carriers and impossible on others, and the actual policies on the carrier websites do not match what the customer service reps say on the phone and do not match what the reservations agents say when you actually try to book. concrete examples from the last 10 days of calls.

airline one tells me on the phone that in-cabin pets must fit in a carrier under the seat that is 17 x 12 x 7.5 inches, and that the dog including the carrier must weigh under 20lb total. otis at 36lb plus a carrier is obviously not flying in-cabin on them, fine, but then the same rep tells me cargo is "totally safe, we do it every day" and quotes me $200 each way. i go to look up their cargo safety record and i cannot find consolidated data anywhere, just individual incident news stories and one industry report that lumps all carriers together. airline two tells me their in-cabin carrier is 18 x 11 x 11 with a 25lb combined weight limit, which is still not otis, and their cargo program does not accept dogs over 30lb between june and september because of "summer heat embargo." airline three has a separate pet program with a 70lb cabin allowance for an extra seat purchase ($400), which would actually work, but the program only operates out of three airports and denver is not one of them, despite the booking page showing me a flight to portland with the pet option as a checkbox during selection. i called them and the rep said the website was wrong and pet-cabin out of denver is not available, even though i could literally have booked it five minutes earlier.

the actual question. how do you cut through this. is there a resource somewhere that compiles actual carrier cargo safety data (incidents per 10,000 animals, not anecdotes), summer heat embargo policies, and the gap between published policy and actual-at-booking reality. and if you have flown a 30 to 40lb dog cross country in the last few years, did you do cargo or did you do the extra-seat in-cabin option, and would you do the same thing again. otis is not a candidate for a 30 hour drive in a moving truck with the cats and i do not want to ship him on a carrier that loses dogs at a higher rate than i could measure if i knew the data. also open to "drive him yourself in a separate car" answers, i have considered it, the math on flights vs a 5 day drive with hotels is not as one-sided as people assume but it is the fallback if the air option is genuinely unsafe